New Tub Install--Old vs. Whirlpool

I am planning on installing a new 60x32 whirlpool tub in place of my existing 60x30 tub. I have not ripped the old tub out yet but am wondering if I am going to run into problems with the drain being off center. If so, how do I fix?

Are there any other issues I should be aware of?

Thanks

The drain will NOT line up. It might be an easy change, but it could be messy...depends on where joists run, and the material the drains are made of (cast iron, pvc, etc.).